Automatic electric fire-alarm



(No new. H. A. EDGECOMB.

AUTOMATIC ELEGTRIQFIRE ALARM. No. 549,906. Patented Nov. 19, 1895.

Witnesses: Ewen/170T: I ,g; 41% Q. EHJVLM AHDIEW LGRMMM. MUTO'UTIIQWMHING'OKIC,

UNITED STATES PATENT OFFICE,

HARRY A. EDGECOMB, OF MECHANIC FALLS,:MAII\ E.

AUTOMATIC ELECTRIC FIRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 549,906, dated November 19, 1895.

Application filed January 5, 1894. $eria1No. 495,862, (No model.)

To aZZ whom it may concern.-

Be it known that 1, HARRY A. EDGECOMB, a citizen of the United States of America, residing at Mechanic Falls, in the county of Androscoggin and State of Maine, have invented certain new and useful Improvements in Automatic Electric Fire-Alarms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in automatic electric fire-alarms.

It is designed to be used alone or in combination with an ordinary push-button.

It consists in a suitable non-conducting base, contact-plates attached to said base and normally out of contact with each other, and an elastic circuit-closer electrically connected with one of said plates and held away from the other by a fusible plug inserted between said circuit-closer and the base, but capable of being brought into contact with the other plate by the fusing of said plug.

It further consists in the combination of an automatic electric fire-alarm and pushbutton.

In the drawings herewith accompanying and forming apart of this specification, Figure 1 is a perspective view of my improved firealarm, the cover and push-button being removed and a part of the base broken away; and Fig. 2 is a central vertical section of the inclosing case and push-button.

Same letters refer to like parts.

In said drawings, a represents a base of some non-conducting material, having a re-- cess Z2 near the circumference sufficient to allow of the insertion of a fusible plug 0. Attached to the face of said base are two metallic plates cl and 6, cl having its free end adapted to be forced into contact with the end of plate c, said plates being connected by the wires 9 and f of an electric circuit. Attached to plate d is a spring h, adapted to be held out of contact with plate 6 by having its end rest against said plug, but so arranged that when said plug is removed or fuses the spring will return until it comes in contact with a lip c, formed by turning up the edge of plate 6, thus completing the circuit and ringing an alar1n-bell.

NVith the exception of the spring and fusible plug the device may be precisely the same as is seen in the ordinary push-button, and if the cover j and button shown in Fig. 2 be placed over the device shown in Fig. 1 I have a combined push-button and automatic fire-alarm.

Aportion of the base of the coverj may be cut away, as seen at m, so as to leave the fusible plug exposed,and a button it, mounted in said cover j, serves to force a contact between the two plates d and e. The plug may be made of material capable of being fused at any desired temperature.

I am aware that automatic fire-alarms have been made in which a fusible plug is interposed directly between the spring and one of the plates, and I do not claim, broadly, such a device.

The advantages of my device are that it is simple in construction, can be readily attached to the ordinary push-button, and is not liable to be prevented from working by the non-conducting plug, which is usually inserted between the spring and one of the plates.

Having thus described my invention and its use, I claim-- 1. In a combined push button and automatic electric fire alarm, a suitable non-conducting base having a fusible plug inserted in a recess in said base, plates attached thereto normally out of contact with each other, a spring attached to one of said plates and having its free end held out of engagement with the other plate by said fusible plug, a cover inclosing said base, plates, spring and plug, and a push button mounted in said cover and adapted to cause acontact between said plates, substantially as and for the purposes set forth.

2. In an automatic electric fire alarm, a suitable base of non-conducting material, contact plates attached thereto normally out of contact with each other, a circuit closing spring attached to one of said plates, a fusible pluginserted in a recess in the circumfer- 100 once of said base and adapted to hold said spring out of eontaet with the other of said plates, and a cover adapted to inelose said base, plates spring and plug, said cover having a portion cut away to expose the outer edge of the plug to the air, substantially as and for the purposes set forth.

In testimony whereof I atfix my signature, in presence 0t two witnesses, this 23d day of December, 1893.

HARRY A. EDGECOMB.

Witnesses:

ELGIN O. VERRILL, NATHAN CLIFFORD. 

